i really doubt that a 28 ft canopy would fit in the smaller nb6 container. i have packed nb6's and i gotta tell ya its tite.extending the container so a 28 would fit would not be legal as an emergency parchute.the faa approves military personel assemblies for use (i dont recall the wording in the f.a.r.s )but unless the container was built with extensions at the factory and there was a military drawing/ contract #, it would nt be legal for use as an emergency parachute.

of course if cossey DID somehow manage to put the much bigger (ABOUT 200 sq feet) and bulkier 28 ft canopy into the smaller nb6 container ,then cooper would likely have had an extremely HARD pull .remember,this was back in the days of cones(which the nb6 and nb8 containers had 4), NOT closing loops. rigs with cones exhibit higher ripcord pull forces than the same container with loops.